Electronic Engineering Hoffman DS 500 Sequencer


EEH DS500 frontplate

EEH baute den Banana Synthy und einige Sonderanfertigungen von Sequenzern für Tangerine Dream und Klaus Schulze.
Wuppertal, Deutschland, etwa 1982 (?), Auflage unbekannt. Benutzt von Klaus Schulze (es gibt ein Foto von KS mit EEG DS500), Till Kopper, Frank Klare und ?
Digitaler 500 Schritte monophoner Sequenzer mit Spannungsausgängen.
Schwarzes Metalgehäuse mit etwa 20/15/6 cm (Breite, Tiefe, Höhe)

EEH built the Banana Synth and some custom sequencers for Tangerine Dream and Klaus Schulze
Wuppertal, Germany, about 1982 (?), # built ? Used by Klaus Schulze (there is one photo of KS with an EEH DS500), Till Kopper, Frank Klare and ?
Digital 500 Steps Sequencer monophonic with Voltage/Gate Interface
Black metal box about 8/6/2.5 inches (width/deep/high).





Vorne / Frontpanel

3 digit 8-segment LED display
speed knob
bypass switch
matrix of 4 rows and 5 colums of buttons:

left colum:
C (= Control Voltage = used as pitch most times) with yellow LED
T (= Time = note value) with yellow LED
D (= Duration = gate time) with yellow LED
L (= loop) with yellow LED


second colum:
7
4
1
0


third colum:
8
5
2
Start/Stop button with red LED


fourth colum:
9
6
3
+ (next step) with red LED


fifth colum:
M (= mode selector/ pushed twice= step recording) with green LED
I (= load extern= "realtime" recording) with green LED
G (= goto/ tape in) with green LED
- (= goto last step/ tape out) with green LED





Hinten / Backpanel

on/off switch
power in (9-15 Volts) 3,5 mm jack
tape in/out as one (1!) RCA socket
(you have to swap jacks to send or receive from tape)
clock out (Voltage trigger)
clock in (dito)
gate out (to be switched from S to V-trigger with mini switches inside the box)
gate in (dito)
CV out (1 Volt/octave / to be finetuned inside the box)
CV in (1 Volt/octave / to be finetuned inside the box)





Innenleben / Inside

EEH DS500 inside detail chips

Durch das Umschalten des Dip-Schalters Nr. 3 auf AUS gibt es am Gate-Ausgang einen V-Gate. Hier steht er auf AN und somit auf Switch-Gate
By setting the dip-switch #3 to OFF, you get a voltage gate out. Here it is set to ON and there for you get S-gate







Und wie zu meistern / How to master

Um eine Schleife eines C-Dur Arpeggio in der zweiten Oktave ab dem Schritt 250 zu programmieren muß man "nur" eintippen:
To program a loop of a C maj arpeggio in the second octave starting at memory location 250 you have "only" to type:

250 G go to step 250
M (2x)enable program mode and selecting step recording (LED of the M-button = on, other green LEDs = off)
200 C 2nd octave no halfstep = C
 unit jumps to the next step after every use of the C, T, D or L command
204 C 2nd octave and 4 halftones above the C = E
207 C 2nd octave and 7 halftones above the C = G
250 L jump to step 250
001 T looping endless, a different value x would loop x times and would go after that to step selected above
250 G goto step 250
004 T note lenght = 4 ticks of the clock
004 T you could also just type T when the value stays the same as before
004 T you could also just type T when the value stays the same as before
250 G go to step 250
003 D note duration = 3 ticks of the clock
003 D you could also just type T when the value stays the same as before
003 D you could also just type T when the value stays the same as before
M (4x)exit program mode (all 4 green LEDs = off)


Wie man sieht war das ganz musikalisch zu programmieren ;-)
As you can see it was really musical to program ;-)

Um die Sequenz abzuspielen muss man:
To play this sequence you have to:
250 G go to step 250
S-button = start/stop





Extras /special

Mein Exemplar hat paar Modifikationen vorne am Gehäuse
On my unit are some special outputs in front of the box

Diese Modifikationen wurden von EEH ausgeführt:
These modifications were made by EEH:
Bitte kontaktieren, wenn Sie Interesse an der MIDI Modifikation haben sollten (MIDI-Buchse, 3 Kabel, 2 Widerstände, neuer EPROM).
Please contact, if you are interested in the MIDI modification (MIDI socket, 3 wires, 2 resistors, new EPROM).

Diese Modifikation wurde kürzlich ausgeführt:
This modification was made recently:


EEH DS500 inside




Quellen /Resources

Copyright: Thomas Hopf (www.elink.de)

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